i generally make butternut squash lasagna based off of that recipe, but with some modifications. i usually use organic baby spinach in place of the swiss chard because that's what's easy to find where i live. i also generally replace the milk with soymilk (unflavored) just because too much dairy sometimes doesn't agree with me.
it's pretty easy to vegan-ize the recipe though. i've made it both dairy and gluten-free by using rice lasagna noodles and rice flour in place of the regular lasagna noodles and flour. i've used soymilk and vegan margarine in place of the milk and butter, and left the parmesan cheese out completely. it doesn't have quite the same flavor without the parmesan cheese, but the white sauce made just with the soymilk, margarine, flour and herbs/spices still comes out tasting really yummy. i have never tried using any sort of vegan parmesan cheese substitute, but if anyone tries it, i'm curious how it turns out.
another frequent modification i make is to use whole wheat lasagna noodles in place of regular. the whole wheaty flavor of the noodles works well with this kind of lasagna.
i've also tried this with frozen already mashed up butternut squash and basically just skip the roasting and just thaw the squash and stir in a smidge of salt and it comes out fine.
i've even tried it with kale instead of chard or spinach and while not my first choice of green to use in this recipe, it's definately one of the only times i've actually found kale to not taste horrible. i know it's good for you, and when i get it from my CSA farm i try to use it, but i mostly have to force myself to eat it, and in this recipe it tasted halfway decent.
as a side note, does anyone else have recipes that make kale taste good? i just don't like the really strong flavor of it in most cases.